Semiconductor device having ferroelectric material and method of producing the same

Abstract

Abstract The structure of a ferroelectric capacitor (C) exists on a source region (23) between a gate electrode (22) and a local oxide film (26). The structure has an upper electrode (30) and a lower electrode (31) between which a ferroelectric film (29) is sandwiched, and has an electrically conductive oxide film (32) between the lower electrode (31) and the source region (23). The electrically conductive oxide film (32) is composed of ITO, ReO₂, RuO₂, MoO₃. In oder to improve crystallinity of the ferroelectric-film (29), the ferroelectric film (29) is annealed with oxygen. Though oxygen infiltrates into the conductive oxide film (32) to some extent, no adverse effect is caused except further oxidation of the conductive oxide film (32). That is, the oxide film serves as a barrier to oxidation or a dummy layer, so that the silicon at the interface with the source is substantially protected from oxidation. Therefore, the decrease in contact resistance and development of series parasitic capacitance are avoided to increase freedom for forming the capacitor region (C) and to increase the degree of integration.

Inventors

• 👤 Kazuhiro Takenaka

Bibliographic Details